Trends in the incidence of primary malignant brain tumors in Taiwan and correlation with comorbidities: A population-based study

OBJECTIVE Primary malignant brain tumors are relatively uncommon, and their incidence and survival rates have seldom been reported. PATIENTS AND METHODS We identified all patients with malignant brain tumors in Taiwan between 1997 and 2012 using the National Health Insurance database. We estimated the stratified incidence of malignant brain tumors by age and sex. We estimated the median 1-, 2-, and 5-year survival, taking comorbidities into account. Trends for incidence and survival were analyzed using Joinpoint regression. The incidence in different geographic areas was also evaluated. RESULTS A total of 7746 men and 5846 women were identified. The incidence of malignant brain tumor was 3.34 (95% CI, 3.09-3.59) per 100,000 person-years in 1997 and 3.82 (95% CI, 3.56-4.08) per 100,000 person-years in 2012. The average annual percentage change (APC) of the standardized incidence over this period was 0.1 (95% CI, -1.9 to 2.2), suggesting a relatively stable incidence. However, the incidence significantly decreased between 1999 and 2012, with an APC of -1.8 [95% CI, -2.5 to -1.0]. One- and 5-year survival was 53.8% (50.0%-57.5%) and 27.5% (24.1%-30.9%) in 1997 and 67.6% (64.3%-70.7%) and 32.8% (29.6%-35.9%) in 2012. The average APC was 1.1 (95% CI, 0.7-1.5) for 1-year survival and 0.2 (95% CI, -1.0-1.4) for 5-year survival. The trend of improvement in the survival rate was seen for short-term but not long-term survival, especially in the group with more comorbidities. CONCLUSIONS A slightly decreased trend in incidence of primary malignant brain tumors was observed in Taiwanese general population since 1999. Over the past 15 years, the short-term survival of malignant brain tumors has improved, especially in adults.